MICRO by Sir Jed Flashcards
He established the germ theory of disease and discovered MTB
a. Jon Snow
b. Robert Koch
c. Louis Pasteur
d. Antoine Van Leeuwenhoek
Robert Koch
An endoscope for intestinal imaging
a. semicritical material
b. Critical materials
c. Noncritical materials
d. NOTA
semicritical material
Antiseptic technique for blood culture
a. 70% alcohol
b. 70% alcohol then 2% iodine
c. 2% Iodine then 70% alcohol
d. Alcohol, iodine, alcohol
70% alcohol then 2% iodine
Used to sterilized HEPA filters in BSC
a. Ethylene oxide
b. Bleach
c. Moist heat
d. Formaldehyde vapor
Formaldehyde vapor
Most resistant microorganism
a. Prion
b. Bacillus
c. Mycobacteria
d. Lipid virus
Bacillus
- Order of Most Resistant to Least: Prions > Spore > mycobacteria > nonlipid virus > Fungi > bacteria >
lipid virus (susceptible to detergent)
Prion is not a microorganism
The ff. is a wrong practice in microbiology lab
a. Keeping shoulder-length hair
b. Wearing of conservative jewelry
c. Wearing crocs in the lab
d. Opening culture plate in BSC
Wearing crocs in the lab
No recirculation of air, total Exhaust via HEPA, BSC II
a. Type A1
b. Type AII
c. Type B1
d. Type B2
Type B2
- Type AI – 70% recirculated thru HEPA (A.22)
- Type AII/B3 – same as IIa, but it can filter toxic chem and radionucleotides
- Type B1 – 30% recirculated thru HEPA (a.22)
- Type B2 – no recirculation, total Exhaust via HEPA
Is the definitive lab reference for questions related to individual test
a. SOP manuals
b. Procedure
c. Reference book
d. NOTA
SOP manuals
instrument maintenance record should be retained
a. for 1 yr
b. for 2 yrs
c. for the life of the instrument
d. for 5 yrs
for the life of the instrument
checking media and reagents with specific organisms to determine whether expected results are obtained and documenting that the instrumentation meets all operating parameters before it is used on patient samples
a. Quality management
b. Quality assurance
c. Quality assessment
d. Quality control
Quality control
The ff. are part of quality assurance except
a. Preanalytical
b. Analytical
c. Post analytical
d. Accuracy and precision
Accuracy and precision
Incubator temperature should be checked
a. Weekly
b. Monthly
c. 4x/ month
d. Daily
Daily
lab must perform QC on all of the ff. media except
a. complex media
b. media made by the lab
c. Commercial media
d. media with a history of failure
Commercial media
- Commercial media are always retested by the manufacturer, but laboratory must obtain a statement of QC from the manufacturer of all media that the lab will not retest
Virus for QC stock should be stored
a. Indefinitely at -70oC
b. 1 yr on TSA
c. thawed and refrozen every 3 yrs
d. NOTA
Indefinitely at -70oC
Choice of collection for C. diphtheriae and N. meningitidis?
a. Sputum
b. Lumbar puncture
c. Nasopharynx
d. Blood
Nasopharynx
Amies, Stuart, or Cary–Blair are NOT suitable for the transport of swabs for culture of most
pathogens except __________
a. C. diphtheriae
b. N. gonorrhoeae
c. N. meningitidis
d. Enterobacteriaceae
N. gonorrhoeae
A patient who took barium should be deferred from submitting stool sample for
a. 4 days
b. 6 days
c. 3 days
d. 2 days
4 days
- 4 to 5 days
The two most common organisms isolated from skin and soft tissue infections/soft tissue abscess
a. S. aureus and C. albicans
b. S. aureus and S. pyogenes
c. S. aureus and E. coli
d. S. aureus and Enterococci
S. aureus and S. pyogenes
method of choice for recovery of anaerobic bacteria from a deep abscess
a. swab in the margin
b. aspirate in the center of lesion
c. aspirate in the margin of lesion
d. swab in the center of lesion
aspirate in the margin of lesion
Calcium Alginate is toxic to
a. Neisseria
b. Virus
c. Chlamydia
d. Aota
Virus
*HSV
The purpose of adding 0.025%–0.050% sodium polyanetholsulfonate (SPS) to nutrient broth
media for the collection of blood cultures
a. Inhibits phagocytosis and complement
b. Inhibits Neisseria and Anaerobes
c. Inhibits antibody
d. Inhibits clotting of blood
Inhibits phagocytosis and complement
This additive should never be used in Microbiology, except
a. Heparin
b. EDTA
c. Citrate
d. NOTA
Heparin
- Heparin = USED FOR VIRAL CULTURES and FOR ISOLATION OF MYCOBACTERIUM SPP.
FROM BLOOD
Specimen should be transported to the laboratory ideally within 30 MINUTES of collection,
preferably within ______
a. 1 hr
b. 2 hrs
c. 3 hrs
d. 4 hrs
2 hrs
The ff. is/are subject for rejection for culture except
a. Saliva
b. unrefrigerated urine more than 2 hours
c. Dried specimen
d. Bone marrow aspirate more than 4 hrs
Bone marrow aspirate more than 4 hrs
- Suboptimal samples FROM INVASIVE PROCEDURE should still be processed SPECIMENS IMPOSSIBLE TO RECOLLECT/From Invasive procedure: Bone marrow, spinal fluid, or surgery (Effusions not included but maybe can be part also)
Which should be processed first?
a. Amniotic fluid from a senior citizen
b. Swabs in holding medium from the first OPD
c. Sputum from the last OPD patient
d. Urine sample from a student
Amniotic fluid from a senior citizen
Smear Preparation: Sample is allowed to air-dry to prevent cell distortion, affixed to slide by placing it on a SLIDE WARMER for at least 10 minutes or by flooding it with __________ for 1 min.
a. 75% ethanol
b. Sulfuric acid
c. Iodine
d. 95% methanol
95% methanol
First step in classification of bacteria
a. Biochemical reaction
b. Colony identification
c. Staining
d. Molecular method
Staining
First step in gram staining?
a. Fixation
b. Crystal violet
c. 95% acetone
d. Safranin O
Crystal violet
This step in gram staining distinguishes gram positive from gram negative bacteria
a. Crystal violet
b. Mordant
c. 95% acetone
d. Safranin O
95% acetone
In viewing a gram-stained smear, the key indicators of an infectious process are
a. Bacteria
b. Phagocytes
c. RBC
d. AOTA
Phagocytes
Gram stain reaction of yeast
a. Positive
b. Negative
c. Variable
d. No gram stain reaction
Positive
Gram positive that appears gram negative
a. Thick smear
b. Under decolorized
c. Less safranin
d. Antibiotic treatment
Antibiotic treatment
In Ziehl-Neelsen, this method will make the cell wall bind to carbolfuschin?
a. Iodine
b. Boiling water
c. Dry heating
d. B and C
B and C
What is the total magnification:
- objective lens 100x magnification
- Ocular lens 10x magnification
a. 200x
b. 110x
c. 100x
d. 1000x
1000x
designed to provide maximum illumination and resolution when observing images
a. Contrasting
b. Kohler illumination
c. Using of filters
d. Fine adjusting knob
Kohler illumination
At least ___bacteria per milliliter of broth are needed for turbidity to be detected with the
unaided eye
a. 10^5
b. 10^4
c. 10^6
d. 10^3
10^6
the proper manner/order of dispensing plated culture media:
a. Weigh -> dissolved in flask -> sterilize -> Dispense
b. Weigh -> Sterilize -> Dissolved in flask -> Dispense
c. Weigh -> dissolved in flask -> Dispense -> Sterilize
d. Any of the ff.
Weigh -> dissolved in flask -> sterilize -> Dispense
contain one or more agents that are inhibitory to all organisms except those “desired” by the
specific growth condition or chemical
a. Enrichment
b. Nutritive
c. Selective
d. Differential
Selective
Enrichment - contain specific nutrients required to enhance the growth of particular bacterial pathogens from a mixture of organisms
Nutritive - contain nutrients that support growth of most nonfastidious organisms without giving any particular organism a growth advantage
Differential - allows colonies of one bacterial species or type to exhibit certain metabolic or
culture characteristics that can be used to distinguish it from other bacteria growing on the
same plate
MacConkey agar is both
a. Nutritive and selective
b. Selective and differential
c. Nutritive and Differential
d. Enrichment and selective
Selective and differential
5-10% Sheep RBC is the most commonly used blood agar because
a. Readily available
b. Less inhibitory
c. Both a and b
d. Inexpensive
Both a and b
- Sheep blood does not support the growth of Haemophilus haemolyticus
Selective and differential for Vibrio spp
a. TSB
b. TCBS
c. XLD
d. MAC with sorbitol
TCBS
A - Trypticase soy broth (TSB) - All-purpose enrichment broth
C - Xylose lysine desoxycholate (XLD) agar - Isolation and differentiation of Salmonella and Shigella spp. from other gram-negative enteric Bacilli
D – For the selection and differentiation of E. coli O157:H7 in stool specimens
primary and differential media of choice for recovery of most fecal pathogens
a. HE, MAC, Campy-blood agar, and CNA
b. MSA, MAC, SS, and Modified Thayer martin
c. MAC, XLD, TCBS, and Regan Lowe
d. MAC, EMB, HE, BCYE
HE, MAC, Campy-blood agar, and CNA
- Hektoen agar selectively isolates pathogenic coliforms, especially Salmonella and Shigella.
MacConkey agar differentiates lactose fermenters from nonfermenters. CNA agar contains antibiotics that prohibit growth of gram-negative coliforms but not gram-positive cocci.
Campy agar contains the antibiotics cephalothin, trimethoprim, vancomycin, polymyxin B, and amphotericin B to prevent growth of Enterobacteriaceae, Pseudomonas spp., and fung
Environmental factor/s influencing growth of bacteria
a. pH
b. Temperature
c. Atmosphere
d. AOTA
AOTA
Laboratory incubator temperature is routinely set to
a. 37C
b. 36C
c. Room temp.
d. 35*C
35*C
most bacterial identification strategies are based on bacterial
a. Phenotype
b. Genotype
c. Characteristics
d. DNA homology
Phenotype
Substances obtained and purified from other microbial organisms
a. Antimicrobial
b. Antibiotic
c. Both a and b
d. Bacteriostatic
Antibiotic
- Antimicrobial agents - natural and synthesized substances: antibacterial, antifungal, antiparasitic, or antiviral agents
Presence of Ca2+ or Mg2+ will render _____________ resistant to aminoglycosides
a. Enterococci
b. P. aeruginosa
c. E.coli
d. S. aureus
P. aeruginosa
What is the standard inoculum in Antimicrobial susceptibility test?
a. 0.5 McFarland
b. Barium chloride
c. 1% sulfuric acid
d. Any of the ff.
0.5 McFarland
- 0.5 McFarland is made up of 1% sulfuric acid + 1.175% barium chloride
In antimicrobial susceptibility test, it must have sterility control which is
a. Well with antimicrobial
b. Well without antimicrobial
c. Well with pure culture
d. Well without pure culture
Well without pure culture
*Growth control – well without antimicrobial
Breakpoints are specific concentrations of _________ that separate susceptible, intermediate, or
resistant?
a. Antimicrobials
b. Pure colony
c. Growth
d. AOTA
Antimicrobials
The ff. will cause false susceptible, except:
a. the agar is too thick
b. Too light inoculum
c. Immediate application of antibiotic disk
d. Immediate placement of culture plates to incubator
the agar is too thick
Immediate placement of culture plates to incubator
Why are plates placed in INVERTED manner inside the incubator?
a. To prevent mold growth
b. To prevent too much drying
c. To prevent buildup of moisture
d. AOTA
To prevent buildup of moisture
What is the first thing to do when removing antibiotic disk from the refrigerator?
a. Do a quality control
b. Warm to room temperature
c. Record the antibiotic disk that is used
d. Apply immediately on the culture plate
Warm to room temperature
The highest antibiotic concentration:
a. Edge
b. Center
c. Between the edge and center
d. Bottom of the agar
Center
As the MICs of the bacterial strains tested increase the corresponding inhibition zone sizes (i.e.,
diameters) ______
a. Increase
b. Decrease
c. Remains the same
d. Can’t be determined
Decrease
An ideal growth for interpreting the plates for antimicrobial susceptibility
a. Nonconfluent
b. Sparse
c. Individual colonies
d. Confluent
Confluent
*Confluent - too numerous to count
For examining the disk diffusion plate, one should use _________ background __________ light
a. White, reflected
b. Dark, transmitted
c. Dark, reflected
d. White, transmitted
Dark, reflected
Plates are examined from the _______ side
a. Front
b. Back
c. Diagonal
d. Top
Back
For media containing blood, a technologist should read or examined the plates from the _____
with lid removed
a. Front
b. Back
c. Diagonal
d. Top
Top
The following growth should be ignored in assessing the plates
a. Swarming of proteus
b. when testing sulfonamides and trimethoprim as a result of the organism population going
through several doubling generations before inhibition/slight growth in the ZOI
c. a and b
d. individual colonies inside the ZOI
a and b
For reading for haze growth of Staphylococci and Enterococci, one should used
a. Reflected light
b. Transmitted light
c. No light
d. Red light
Transmitted light
Individual colonies inside the ZOI
a. Mixed colony
b. Resistant colony
c. Mutated colony
d. AOTA
AOTA
Positive for B-lactamase
a. N. gonorrhoeae
b. Moraxella
c. Haemophilus
d. AOTA
AOTA
To detect inducible clindamycin resistance in MRSA isolates that are resistant to erythromycin & susceptible to clindamycin on initial testing
a. E test
b. D test
c. Carbapenem
d. B lactamase test
D test
Growth slows down,competition for food, temp changes, waste accumulation
a. Lag
b. Log
c. Stationary
d. Decline
Stationary
i. Lag phase – slow microbial growth, microbe increase size-preparing to divide
ii. Log phase – exponential growth (anaerobes more sensitive to O2 at this phase)
iii. Plateau/stationary – Growth slows down, competition for food, temp changes, waste accum.
iv. Decline/death – more dead that living. Bacteria die.
Released by Dead bacteria, causes cytokine storm, not potent and Heat stable
a. Gram positive
b. Exotoxin
c. TSST
d. Endotoxin
Endotoxin
Mediated by viruses, by which DNA from two bacteria may come together in one cell
a. Transformation
b. Transduction
c. Conjugation
d. Transposon
Transduction
Fermentation end-products:
a. Lactic and mixed acids
b. Alcohols
c. CO2
d. AOTA
AOTA
Positive reaction for catalase test?
a. CO2 and Water
b. O2 and Water
c. O2 and CO2
d. NO2 and water
O2 and Water
the hallmark of the staphylococcal enterotoxins is that because the toxins are preformed in the
contaminated food; the organism does not need to grow in the host and therefore the action is
very rapid
a. 1st statement is correct
b. 2nd statement is correct
c. Both statements are incorrect
d. Both statements are correct
Both statements are correct
Test that differentiates Staphylococcus from Streptococcus
a. Catalase
b. Coagulase
c. Bacitracin
d. Lysostaphin
Catalase
The toxins, which are often found in milk products, are associated with pseudomembranous
enterocolitis and toxic shock syndrome, and they may exacerbate the normal immune response, resulting in further tissue damage and systemic pathology.
a. Endotoxin
b. Neurotoxin
c. Enterotoxin
d. AOTA
Enterotoxin
Inhibitor in MSA
a. Mannitol
b. 7.5% NaCl
c. Alcohol
d. Colistin
7.5% NaCl
Most common cause of hospital acquired UTI
a. S. epidermidis
b. S. saprophyticus
c. K .pneumoniae
d. UPEC
S. epidermidis
Reagent for optochin test
a. ethylhydrocupreine hydrochloride
b. Sodium Deoxycholate
c. Ninhydrin
d. Sheep plasma
ethylhydrocupreine hydrochloride
A throat culture was request by a physician, what is the most likely specmien to be isolated?
a. Group A Streptococcus
b. Group B Streptococcus
c. Group C Streptococcus
d. Group G Streptococcus
Group A Streptococcus
Alternative for anaerobic jar for N.gonorrhoeae?
a. Thayer martin
b. Modified Thayer martin
c. Martin-Lewis
d. Candle Jar
Candle Jar
*Hasten growth of fastidious org (A.22
Neisseria are oxidase positive, the ff. can be a valid procedure for oxidase test
a. Drop the reagent on the colony directly
b. Rub the colony on the paper then drop reagent
c. Rub the colony on paper containing reagent
d. AOTA
AOTA
Cold enrichment is ideal for growth of
a. C. diphtheriae
b. L. monocytogenes
c. Clostridium
d. Bacillus
L. monocytogenes
most common isolated species of Bacillus in opportunistic infections such as bacteremia, post
traumatic infections of the eye, and endocarditis
-motile
-hemolytic
-Penicillin Resistant
-negative string of pearl
-Frosted glass colony
a. B. subtilis
b. B. thuringiensis
c. B. anthracis
d. B. cereus
B. cereus
To manifest the Lecithinase of C. perfringens, one should use
a. SBA
b. EYA
c. CNA
d. CIN
EYA
Found in sealed vacuum bacon?
a. Lactobacillus
b. Listeria
c. Corynebacterium
d. Nocardia
Lactobacillus
Nonphotochromogen; Slow grower, Nitrate positive, Catalase positive, and Niacin positive
a. M. phlei
b. MTB
c. MAC
d. M. leprae
MTB
Specimen/s for MTB identification
a. Urine
b. Feces
c. Blood
d. AOTA
AOTA
Specimens: urine, feces, blood, CSF, tissue biopsies, and aspirations of any tissue or organ
Swab is discouraged
Identify the bacteria
-Oxidase negative
-PAD positive
-TSI: K/A
-H2S: negative
-Citrate negative
a. P. mirabilis
b. P. vulgaris
c. Morganella
d. P. rettgeri
Morganella
Proteus – HS2 Positive
Providencia- citrate positive
Identify the bacteria
-Oxidase negative
-PAD Negative
-TSI: A/A
-H2S negative
-IMVC: ++–
a. K.pneumoniae
b. Serratia
c. Enterobacter
d. E.coli
E.coli
Identify the bacteria
-Oxidase negative
-TSI: K/A
-mannitol negative
-nonmotile
a. S. flexneri
b. S. dysenteriae
c. S. boydii
d. S. sonnei
S. dysenteriae
The difference between TSI and Kliger’s iron is
a. The former uses Lactose, glucose, and sucrose
b. The latter uses glucose and lactose
c. Both a and b
d. NOTA
Both a and b
True about P.aeruginosa, except
a. Leading cause of nosocomial respiratory tract infection
b. Pyocyanin is P. aeruginosa-specific
c. Grows in Cetrimide agar
d. NOTA
NOTA
Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is an advanced chemical technique that uses ___ excitation to ionize chemical functional groups that
are included in the proteins of an organism
a. Heat
b. Fluorescent
c. Laser
d. Oxidation-reduction
Laser
Bordetella spp. are inhibited by fatty acid, therefore, one should use_______
a. Cotton
b. Charcoal
c. Calcium alginate
d. Wood
Charcoal
Which among the ff. is not an obligate intracellular, no peptidoglycan in cell wall, but grow on
nonliving media?
a. Chlamydiae
b. Rickettsiae
c. Mycoplasmas
d. Viruses
?
True about Spirochetes, except
a. Facultative anaerobe
b. Gram negative like outer membrane
c. Has external flagella for motility
d. Has insertion disk
Has external flagella for motility
- Axial filaments/periplasmic flagella/endoflagella for motility
“Interstitial keratitis, Huntchinsonian teeth, and Nerve deafness” are called
a. Hutchinsonian triad
b. Gummas
c. Condylomata lata
d. Hard chancre
Hutchinsonian triad
For detection of C. neoformans in CSF?
a. Methenamine silver stain
b. Lactophenol cotton blue
c. India ink
d. PAS stain
India ink
Characteristic/s of AIDS
a. CD4:CD8 ratio - 0.5:1
b. CD4 count below 200/uL
c. Opportunistic infections or malignancy or both
d. AOTA
AOTA
